/*
 * decap.c: gtpu tunnel decap packet processing
 *
 * Copyright (c) 2017 Intel and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <vlib/vlib.h>
#include <vnet/pg/pg.h>
#include <upf/upf.h>
#include <upf/upf_pfcp.h>

#if CLIB_DEBUG > 1
#define upf_debug clib_warning
#else
#define upf_debug(...)				\
  do { } while (0)
#endif

typedef enum
{
  UPF_GTPU_INPUT_NEXT_DROP,
  UPF_GTPU_INPUT_NEXT_IP4_FLOW_PROCESS,
  UPF_GTPU_INPUT_NEXT_IP6_FLOW_PROCESS,
  UPF_GTPU_INPUT_NEXT_IP4_PROCESS,
  UPF_GTPU_INPUT_NEXT_IP6_PROCESS,
  UPF_GTPU_INPUT_NEXT_ERROR_INDICATION,
  UPF_GTPU_INPUT_NEXT_ECHO_REQUEST,
  UPF_GTPU_INPUT_N_NEXT,
} gtpu_input_next_t;

typedef struct
{
  u32 next_index;
  u32 session_index;
  u32 error;
  u32 teid;
} gtpu_rx_trace_t;

static u8 *
format_gtpu_rx_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  gtpu_rx_trace_t *t = va_arg (*args, gtpu_rx_trace_t *);

  if (t->next_index == UPF_GTPU_INPUT_NEXT_ERROR_INDICATION)
    {
      /*
       * In this case, session index is retrieved on the error
       * indication node, so let's not add a misleading error message
       */
      s = format (s, "received GTPU Error Indication");
    }
  else if (t->session_index != ~0)
    {
      s =
	format (s,
		"GTPU decap from gtpu_session%d teid 0x%08x next %d error %d",
		t->session_index, t->teid, t->next_index, t->error);
    }
  else
    {
      s =
	format (s,
		"GTPU decap error - session for teid 0x%08x does not exist",
		t->teid);
    }
  return s;
}

always_inline uword
upf_gtpu_signalling_msg (gtpu_header_t * gtpu, u32 * error)
{
  if (PREDICT_FALSE ((gtpu->ver_flags & GTPU_S_BIT) == 0))
    {
      *error = UPF_GTPU_ERROR_NO_ECHO_REQUEST_SEQ;
      return UPF_GTPU_INPUT_NEXT_DROP;
    }

  switch (gtpu->type)
    {
    case GTPU_TYPE_ECHO_REQUEST:
      return UPF_GTPU_INPUT_NEXT_ECHO_REQUEST;

    case GTPU_TYPE_ECHO_RESPONSE:
      // TODO next0 = UPF_GTPU_INPUT_NEXT_ECHO_RESPONSE;
      return UPF_GTPU_INPUT_NEXT_DROP;

    default:
      return UPF_GTPU_INPUT_NEXT_DROP;
    }
}

always_inline uword
upf_gtpu_input (vlib_main_t * vm,
		vlib_node_runtime_t * node, vlib_frame_t * from_frame,
		u8 is_ip4)
{
  u32 n_left_from, next_index, *from, *to_next;
  upf_main_t *gtm = &upf_main;
  u32 last_session_index = ~0;
  u32 last_rule_index = ~0;
  gtpu4_tunnel_key_t last_key4;
  clib_bihash_kv_24_8_t last_key6;
  u32 pkts_decapsulated = 0;

  if (is_ip4)
    last_key4.as_u64 = ~0;
  else
    memset (&last_key6, 0xff, sizeof (last_key6));

  from = vlib_frame_vector_args (from_frame);
  n_left_from = from_frame->n_vectors;

  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
      while (n_left_from >= 4 && n_left_to_next >= 2)
	{
	  u32 bi0, bi1;
	  vlib_buffer_t *b0, *b1;
	  u32 next0, next1;
	  ip4_header_t *ip4_0, *ip4_1;
	  ip6_header_t *ip6_0, *ip6_1;
	  gtpu_header_t *gtpu0, *gtpu1;
	  u32 gtpu_hdr_len0 = 0, gtpu_hdr_len1 = 0;
	  u32 session_index0, session_index1;
	  u32 rule_index0, rule_index1;
	  upf_session_t *t0, *t1;
	  gtpu4_tunnel_key_t key4_0, key4_1;
	  u32 error0, error1;
	  u16 hdr_len0, hdr_len1;

	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t *p2, *p3;

	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);

	    vlib_prefetch_buffer_header (p2, LOAD);
	    vlib_prefetch_buffer_header (p3, LOAD);

	    CLIB_PREFETCH (p2->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
	    CLIB_PREFETCH (p3->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
	  }

	  bi0 = from[0];
	  bi1 = from[1];
	  to_next[0] = bi0;
	  to_next[1] = bi1;
	  from += 2;
	  to_next += 2;
	  n_left_to_next -= 2;
	  n_left_from -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);

	  vnet_buffer (b0)->l4_hdr_offset = b0->current_data;
	  vnet_buffer (b1)->l4_hdr_offset = b1->current_data;

	  /* udp leaves current_data pointing at the gtpu header */
	  gtpu0 = vlib_buffer_get_current (b0);
	  gtpu1 = vlib_buffer_get_current (b1);
	  hdr_len0 = is_ip4 ? sizeof (*ip4_0) : sizeof (*ip6_0);
	  hdr_len0 += sizeof (udp_header_t);
	  hdr_len1 = is_ip4 ? sizeof (*ip4_1) : sizeof (*ip6_1);
	  hdr_len1 += sizeof (udp_header_t);

	  if (is_ip4)
	    {
	      vlib_buffer_advance
		(b0, -(word) (sizeof (udp_header_t) + sizeof (ip4_header_t)));
	      vlib_buffer_advance
		(b1, -(word) (sizeof (udp_header_t) + sizeof (ip4_header_t)));
	      ip4_0 = vlib_buffer_get_current (b0);
	      ip4_1 = vlib_buffer_get_current (b1);
	    }
	  else
	    {
	      vlib_buffer_advance
		(b0, -(word) (sizeof (udp_header_t) + sizeof (ip6_header_t)));
	      vlib_buffer_advance
		(b1, -(word) (sizeof (udp_header_t) + sizeof (ip6_header_t)));
	      ip6_0 = vlib_buffer_get_current (b0);
	      ip6_1 = vlib_buffer_get_current (b1);
	    }

	  session_index0 = ~0;
	  error0 = 0;

	  session_index1 = ~0;
	  error1 = 0;

	  if (PREDICT_FALSE
	      ((gtpu0->ver_flags & GTPU_VER_MASK) != GTPU_V1_VER))
	    {
	      error0 = UPF_GTPU_ERROR_BAD_VER;
	      next0 = UPF_GTPU_INPUT_NEXT_DROP;
	      goto trace0;
	    }

	  if (PREDICT_FALSE (gtpu0->type != GTPU_TYPE_GTPU))
	    {
	      switch (gtpu0->type)
		{
		case GTPU_TYPE_ERROR_IND:
		  UPF_ENTER_SUBGRAPH (b0, ~0, is_ip4);
		  next0 = UPF_GTPU_INPUT_NEXT_ERROR_INDICATION;
		  break;

		case GTPU_TYPE_ECHO_REQUEST:
		case GTPU_TYPE_ECHO_RESPONSE:
		  UPF_ENTER_SUBGRAPH (b0, ~0, is_ip4);
		  next0 = upf_gtpu_signalling_msg (gtpu0, &error0);
		  break;

		default:
		  next0 = UPF_GTPU_INPUT_NEXT_DROP;
		  break;
		}

	      goto trace0;
	    }

	  /* Manipulate packet 0 */
	  if (is_ip4)
	    {
	      key4_0.dst = ip4_0->dst_address.as_u32;
	      key4_0.teid = clib_net_to_host_u32 (gtpu0->teid);

	      /* Make sure GTPU tunnel exist according to packet destination IP and teid
	       * destination identifies a GTP-U entity, and teid identifies a tunnel
	       * on a given GTP-U entity */
	      if (PREDICT_FALSE (key4_0.as_u64 != last_key4.as_u64))
		{
		  clib_bihash_kv_8_8_t kv, value;

		  kv.key = key4_0.as_u64;

		  if (PREDICT_FALSE
		      (clib_bihash_search_8_8
		       (&gtm->v4_tunnel_by_key, &kv, &value)))
		    {
		      error0 = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
		      upf_gtpu_error_ind (b0, is_ip4);
		      next0 = UPF_GTPU_INPUT_NEXT_DROP;
		      goto trace0;
		    }
		  last_key4.as_u64 = key4_0.as_u64;
		  session_index0 = last_session_index =
		    (value.value & 0xffffffff);
		  rule_index0 = last_rule_index = value.value >> 32;
		}
	      else
		{
		  session_index0 = last_session_index;
		  rule_index0 = last_rule_index;
		}
	      t0 = pool_elt_at_index (gtm->sessions, session_index0);

	      goto next0;	/* valid packet */

	    }
	  else			/* !is_ip4 */
	    {
	      clib_bihash_kv_24_8_t kv, value;

	      kv.key[0] = ip6_0->dst_address.as_u64[0];
	      kv.key[1] = ip6_0->dst_address.as_u64[1];
	      kv.key[2] = clib_net_to_host_u32 (gtpu0->teid);

	      /* Make sure GTPU tunnel exist according to packet destination IP and teid
	       * destination identifies a GTP-U entity, and teid identifies a tunnel
	       * on a given GTP-U entity */
	      if (PREDICT_FALSE
		  (memcmp (&kv.key, &last_key6.key, sizeof (last_key6.key)) !=
		   0))
		{
		  if (PREDICT_FALSE
		      (clib_bihash_search_24_8
		       (&gtm->v6_tunnel_by_key, &kv, &value)))
		    {
		      error0 = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
		      upf_gtpu_error_ind (b0, is_ip4);
		      next0 = UPF_GTPU_INPUT_NEXT_DROP;
		      goto trace0;
		    }
		  clib_memcpy (&last_key6.key, &kv.key, sizeof (kv.key));
		  session_index0 = last_session_index =
		    (value.value & 0xffffffff);
		  rule_index0 = last_rule_index = value.value >> 32;
		}
	      else
		{
		  session_index0 = last_session_index;
		  rule_index0 = last_rule_index;
		}
	      t0 = pool_elt_at_index (gtm->sessions, session_index0);

	      goto next0;	/* valid packet */
	    }

	next0:
	  /* Manipulate gtpu header */
	  if (PREDICT_FALSE ((gtpu0->ver_flags & GTPU_E_S_PN_BIT) != 0))
	    {
	      gtpu_hdr_len0 = sizeof (gtpu_header_t);

	      if (PREDICT_FALSE ((gtpu0->ver_flags & GTPU_E_BIT) != 0))
		{
		  gtpu_ext_header_t *ext =
		    (gtpu_ext_header_t *) & gtpu0->next_ext_type;
		  u8 *end = vlib_buffer_get_tail (b0);

		  while ((u8 *) ext < end && ext->type != 0)
		    {
		      if (PREDICT_FALSE (!ext->len))
			{
			  error0 = UPF_GTPU_ERROR_LENGTH_ERROR;
			  next0 = UPF_GTPU_INPUT_NEXT_DROP;
			  goto trace0;
			}

		      /* gtpu_ext_header_t is 4 bytes and the len is in units of 4 */
		      gtpu_hdr_len0 += ext->len * 4;
		      ext += ext->len * 4 / sizeof (*ext);
		    }
		}
	    }
	  else
	    {
	      gtpu_hdr_len0 = sizeof (gtpu_header_t) - 4;
	    }

	  hdr_len0 += gtpu_hdr_len0;
	  UPF_ENTER_SUBGRAPH (b0, session_index0, is_ip4);
	  upf_buffer_opaque (b0)->gtpu.data_offset = hdr_len0;
	  upf_buffer_opaque (b0)->gtpu.ext_hdr_len =
	    gtpu_hdr_len0 - (sizeof (gtpu_header_t) - 4);
	  upf_buffer_opaque (b0)->gtpu.hdr_flags = gtpu0->ver_flags;
	  upf_buffer_opaque (b0)->gtpu.teid =
	    clib_net_to_host_u32 (gtpu0->teid);
	  upf_buffer_opaque (b0)->gtpu.pdr_idx =
	    !(pfcp_get_rules (t0, PFCP_ACTIVE)->flags & PFCP_CLASSIFY) ?
	    rule_index0 : ~0;
	  upf_buffer_opaque (b0)->gtpu.flow_id = ~0;

	  if (PREDICT_FALSE ((hdr_len0 + sizeof (*ip4_0)) >=
			     vlib_buffer_length_in_chain (vm, b0)))
	    {
	      error0 = UPF_GTPU_ERROR_LENGTH_ERROR;
	      next0 = UPF_GTPU_INPUT_NEXT_DROP;
	      goto trace0;
	    }

	  /* inner IP header */
	  ip4_0 = vlib_buffer_get_current (b0) + hdr_len0;
	  if ((ip4_0->ip_version_and_header_length & 0xF0) == 0x40)
	    next0 = (~0 == upf_buffer_opaque (b0)->gtpu.pdr_idx) ?
	      UPF_GTPU_INPUT_NEXT_IP4_FLOW_PROCESS :
	      UPF_GTPU_INPUT_NEXT_IP4_PROCESS;
	  else
	    next0 = (~0 == upf_buffer_opaque (b0)->gtpu.pdr_idx) ?
	      UPF_GTPU_INPUT_NEXT_IP6_FLOW_PROCESS :
	      UPF_GTPU_INPUT_NEXT_IP6_PROCESS;

	  pkts_decapsulated++;

	trace0:
	  b0->error = error0 ? node->errors[error0] : 0;

	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      gtpu_rx_trace_t *tr
		= vlib_add_trace (vm, node, b0, sizeof (*tr));
	      tr->next_index = next0;
	      tr->error = error0;
	      tr->session_index = session_index0;
	      tr->teid = clib_net_to_host_u32 (gtpu0->teid);
	    }

	  if (PREDICT_FALSE
	      ((gtpu1->ver_flags & GTPU_VER_MASK) != GTPU_V1_VER))
	    {
	      error1 = UPF_GTPU_ERROR_BAD_VER;
	      next1 = UPF_GTPU_INPUT_NEXT_DROP;
	      goto trace1;
	    }

	  if (PREDICT_FALSE (gtpu1->type != GTPU_TYPE_GTPU))
	    {
	      switch (gtpu1->type)
		{
		case GTPU_TYPE_ERROR_IND:
		  UPF_ENTER_SUBGRAPH (b1, ~0, is_ip4);
		  next1 = UPF_GTPU_INPUT_NEXT_ERROR_INDICATION;
		  break;

		case GTPU_TYPE_ECHO_REQUEST:
		case GTPU_TYPE_ECHO_RESPONSE:
		  UPF_ENTER_SUBGRAPH (b1, ~0, is_ip4);
		  next1 = upf_gtpu_signalling_msg (gtpu1, &error1);
		  break;

		default:
		  next1 = UPF_GTPU_INPUT_NEXT_DROP;
		  break;
		}

	      goto trace1;
	    }

	  /* Manipulate packet 1 */
	  if (is_ip4)
	    {
	      key4_1.dst = ip4_1->dst_address.as_u32;
	      key4_1.teid = clib_net_to_host_u32 (gtpu1->teid);

	      /* Make sure GTPU tunnel exist according to packet destination IP and teid
	       * destination identifies a GTP-U entity, and teid identifies a tunnel
	       * on a given GTP-U entity */
	      if (PREDICT_FALSE (key4_1.as_u64 != last_key4.as_u64))
		{
		  clib_bihash_kv_8_8_t kv, value;

		  kv.key = key4_1.as_u64;

		  if (PREDICT_FALSE
		      (clib_bihash_search_8_8
		       (&gtm->v4_tunnel_by_key, &kv, &value)))
		    {
		      error1 = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
		      upf_gtpu_error_ind (b1, is_ip4);
		      next1 = UPF_GTPU_INPUT_NEXT_DROP;
		      goto trace1;
		    }
		  last_key4.as_u64 = key4_1.as_u64;
		  session_index1 = last_session_index =
		    (value.value & 0xffffffff);
		  rule_index1 = last_rule_index = value.value >> 32;
		}
	      else
		{
		  session_index1 = last_session_index;
		  rule_index1 = last_rule_index;
		}
	      t1 = pool_elt_at_index (gtm->sessions, session_index1);

	      goto next1;	/* valid packet */

	    }
	  else			/* !is_ip4 */
	    {
	      clib_bihash_kv_24_8_t kv, value;

	      kv.key[0] = ip6_1->dst_address.as_u64[0];
	      kv.key[1] = ip6_1->dst_address.as_u64[1];
	      kv.key[2] = clib_net_to_host_u32 (gtpu1->teid);

	      /* Make sure GTPU tunnel exist according to packet destination IP and teid
	       * destination identifies a GTP-U entity, and teid identifies a tunnel
	       * on a given GTP-U entity */
	      if (PREDICT_FALSE
		  (memcmp (&kv.key, &last_key6.key, sizeof (last_key6.key)) !=
		   0))
		{
		  if (PREDICT_FALSE
		      (clib_bihash_search_24_8
		       (&gtm->v6_tunnel_by_key, &kv, &value)))
		    {
		      error1 = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
		      upf_gtpu_error_ind (b1, is_ip4);
		      next1 = UPF_GTPU_INPUT_NEXT_DROP;
		      goto trace1;
		    }
		  clib_memcpy (&last_key6.key, &kv.key, sizeof (kv.key));
		  session_index1 = last_session_index =
		    (value.value & 0xffffffff);
		  rule_index1 = last_rule_index = value.value >> 32;
		}
	      else
		{
		  session_index1 = last_session_index;
		  rule_index1 = last_rule_index;
		}
	      t1 = pool_elt_at_index (gtm->sessions, session_index1);

	      goto next1;	/* valid packet */
	    }

	next1:
	  /* Manipulate gtpu header */
	  if (PREDICT_FALSE ((gtpu1->ver_flags & GTPU_E_S_PN_BIT) != 0))
	    {
	      gtpu_hdr_len1 = sizeof (gtpu_header_t);

	      if (PREDICT_FALSE ((gtpu1->ver_flags & GTPU_E_BIT) != 0))
		{
		  gtpu_ext_header_t *ext =
		    (gtpu_ext_header_t *) & gtpu1->next_ext_type;
		  u8 *end = vlib_buffer_get_tail (b1);

		  while ((u8 *) ext < end && ext->type != 0)
		    {
		      if (PREDICT_FALSE (!ext->len))
			{
			  error1 = UPF_GTPU_ERROR_LENGTH_ERROR;
			  next1 = UPF_GTPU_INPUT_NEXT_DROP;
			  goto trace1;
			}

		      /* gtpu_ext_header_t is 4 bytes and the len is in units of 4 */
		      gtpu_hdr_len1 += ext->len * 4;
		      ext += ext->len * 4 / sizeof (*ext);
		    }
		}
	    }
	  else
	    {
	      gtpu_hdr_len1 = sizeof (gtpu_header_t) - 4;
	    }

	  hdr_len1 += gtpu_hdr_len1;
	  UPF_ENTER_SUBGRAPH (b1, session_index1, is_ip4);
	  upf_buffer_opaque (b1)->gtpu.data_offset = hdr_len1;
	  upf_buffer_opaque (b1)->gtpu.ext_hdr_len =
	    gtpu_hdr_len1 - (sizeof (gtpu_header_t) - 4);
	  upf_buffer_opaque (b1)->gtpu.hdr_flags = gtpu1->ver_flags;
	  upf_buffer_opaque (b1)->gtpu.teid =
	    clib_net_to_host_u32 (gtpu1->teid);
	  upf_buffer_opaque (b1)->gtpu.pdr_idx =
	    !(pfcp_get_rules (t1, PFCP_ACTIVE)->flags & PFCP_CLASSIFY) ?
	    rule_index1 : ~0;
	  upf_buffer_opaque (b1)->gtpu.flow_id = ~0;

	  if (PREDICT_FALSE ((hdr_len1 + sizeof (*ip4_1)) >=
			     vlib_buffer_length_in_chain (vm, b1)))
	    {
	      error1 = UPF_GTPU_ERROR_LENGTH_ERROR;
	      next1 = UPF_GTPU_INPUT_NEXT_DROP;
	      goto trace1;
	    }

	  /* inner IP header */
	  ip4_1 = vlib_buffer_get_current (b1) + hdr_len1;
	  if ((ip4_1->ip_version_and_header_length & 0xF0) == 0x40)
	    next1 = (~0 == upf_buffer_opaque (b1)->gtpu.pdr_idx) ?
	      UPF_GTPU_INPUT_NEXT_IP4_FLOW_PROCESS :
	      UPF_GTPU_INPUT_NEXT_IP4_PROCESS;
	  else
	    next1 = (~0 == upf_buffer_opaque (b1)->gtpu.pdr_idx) ?
	      UPF_GTPU_INPUT_NEXT_IP6_FLOW_PROCESS :
	      UPF_GTPU_INPUT_NEXT_IP6_PROCESS;

	  pkts_decapsulated++;

	trace1:
	  b1->error = error1 ? node->errors[error1] : 0;

	  if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      gtpu_rx_trace_t *tr
		= vlib_add_trace (vm, node, b1, sizeof (*tr));
	      tr->next_index = next1;
	      tr->error = error1;
	      tr->session_index = session_index1;
	      tr->teid = clib_net_to_host_u32 (gtpu1->teid);
	    }

	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, bi1, next0, next1);
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  u32 next0;
	  ip4_header_t *ip4_0;
	  ip6_header_t *ip6_0;
	  gtpu_header_t *gtpu0;
	  u32 gtpu_hdr_len0 = 0;
	  u32 session_index0;
	  u32 rule_index0;
	  upf_session_t *t0;
	  gtpu4_tunnel_key_t key4_0;
	  u32 error0;
	  u16 hdr_len0;

	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);

	  vnet_buffer (b0)->l4_hdr_offset = b0->current_data;

	  /* udp leaves current_data pointing at the gtpu header */
	  gtpu0 = vlib_buffer_get_current (b0);
	  hdr_len0 = is_ip4 ? sizeof (*ip4_0) : sizeof (*ip6_0);
	  hdr_len0 += sizeof (udp_header_t);

	  if (is_ip4)
	    {
	      vlib_buffer_advance
		(b0, -(word) (sizeof (udp_header_t) + sizeof (ip4_header_t)));
	      ip4_0 = vlib_buffer_get_current (b0);
	    }
	  else
	    {
	      vlib_buffer_advance
		(b0, -(word) (sizeof (udp_header_t) + sizeof (ip6_header_t)));
	      ip6_0 = vlib_buffer_get_current (b0);
	    }

	  session_index0 = ~0;
	  error0 = 0;

	  if (PREDICT_FALSE
	      ((gtpu0->ver_flags & GTPU_VER_MASK) != GTPU_V1_VER))
	    {
	      error0 = UPF_GTPU_ERROR_BAD_VER;
	      next0 = UPF_GTPU_INPUT_NEXT_DROP;
	      goto trace00;
	    }

	  if (PREDICT_FALSE (gtpu0->type != GTPU_TYPE_GTPU))
	    {
	      switch (gtpu0->type)
		{
		case GTPU_TYPE_ERROR_IND:
		  UPF_ENTER_SUBGRAPH (b0, ~0, is_ip4);
		  next0 = UPF_GTPU_INPUT_NEXT_ERROR_INDICATION;
		  break;

		case GTPU_TYPE_ECHO_REQUEST:
		case GTPU_TYPE_ECHO_RESPONSE:
		  UPF_ENTER_SUBGRAPH (b0, ~0, is_ip4);
		  next0 = upf_gtpu_signalling_msg (gtpu0, &error0);
		  break;

		default:
		  next0 = UPF_GTPU_INPUT_NEXT_DROP;
		  break;
		}

	      goto trace00;
	    }

	  if (is_ip4)
	    {
	      key4_0.dst = ip4_0->dst_address.as_u32;
	      key4_0.teid = clib_net_to_host_u32 (gtpu0->teid);

	      /* Make sure GTPU tunnel exist according to packet destination IP and teid
	       * destination identifies a GTP-U entity, and teid identifies a tunnel
	       * on a given GTP-U entity */
	      if (PREDICT_FALSE (key4_0.as_u64 != last_key4.as_u64))
		{
		  clib_bihash_kv_8_8_t kv, value;

		  kv.key = key4_0.as_u64;

		  if (PREDICT_FALSE
		      (clib_bihash_search_8_8
		       (&gtm->v4_tunnel_by_key, &kv, &value)))
		    {
		      error0 = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
		      upf_gtpu_error_ind (b0, is_ip4);
		      next0 = UPF_GTPU_INPUT_NEXT_DROP;
		      goto trace00;
		    }
		  last_key4.as_u64 = key4_0.as_u64;
		  session_index0 = last_session_index =
		    (value.value & 0xffffffff);
		  rule_index0 = last_rule_index = value.value >> 32;
		}
	      else
		{
		  session_index0 = last_session_index;
		  rule_index0 = last_rule_index;
		}
	      t0 = pool_elt_at_index (gtm->sessions, session_index0);

	      goto next00;	/* valid packet */

	    }
	  else			/* !is_ip4 */
	    {
	      clib_bihash_kv_24_8_t kv, value;

	      kv.key[0] = ip6_0->dst_address.as_u64[0];
	      kv.key[1] = ip6_0->dst_address.as_u64[1];
	      kv.key[2] = clib_net_to_host_u32 (gtpu0->teid);

	      /* Make sure GTPU tunnel exist according to packet destination IP and teid
	       * destination identifies a GTP-U entity, and teid identifies a tunnel
	       * on a given GTP-U entity */
	      if (PREDICT_FALSE
		  (memcmp (&kv.key, &last_key6.key, sizeof (last_key6.key)) !=
		   0))
		{
		  if (PREDICT_FALSE
		      (clib_bihash_search_24_8
		       (&gtm->v6_tunnel_by_key, &kv, &value)))
		    {
		      error0 = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
		      upf_gtpu_error_ind (b0, is_ip4);
		      next0 = UPF_GTPU_INPUT_NEXT_DROP;
		      goto trace00;
		    }
		  clib_memcpy (&last_key6.key, &kv.key, sizeof (kv.key));
		  session_index0 = last_session_index =
		    (value.value & 0xffffffff);
		  rule_index0 = last_rule_index = value.value >> 32;
		}
	      else
		{
		  session_index0 = last_session_index;
		  rule_index0 = last_rule_index;
		}
	      t0 = pool_elt_at_index (gtm->sessions, session_index0);

	      goto next00;	/* valid packet */
	    }

	next00:
	  /* Manipulate gtpu header */
	  if (PREDICT_FALSE ((gtpu0->ver_flags & GTPU_E_S_PN_BIT) != 0))
	    {
	      gtpu_hdr_len0 = sizeof (gtpu_header_t);

	      if (PREDICT_FALSE ((gtpu0->ver_flags & GTPU_E_BIT) != 0))
		{
		  gtpu_ext_header_t *ext =
		    (gtpu_ext_header_t *) & gtpu0->next_ext_type;
		  u8 *end = vlib_buffer_get_tail (b0);

		  while ((u8 *) ext < end && ext->type != 0)
		    {
		      if (PREDICT_FALSE (!ext->len))
			{
			  error0 = UPF_GTPU_ERROR_LENGTH_ERROR;
			  next0 = UPF_GTPU_INPUT_NEXT_DROP;
			  goto trace00;
			}

		      /* gtpu_ext_header_t is 4 bytes and the len is in units of 4 */
		      gtpu_hdr_len0 += ext->len * 4;
		      ext += ext->len * 4 / sizeof (*ext);
		    }
		}
	    }
	  else
	    {
	      gtpu_hdr_len0 = sizeof (gtpu_header_t) - 4;
	    }

	  hdr_len0 += gtpu_hdr_len0;
	  UPF_ENTER_SUBGRAPH (b0, session_index0, is_ip4);
	  upf_buffer_opaque (b0)->gtpu.data_offset = hdr_len0;
	  upf_buffer_opaque (b0)->gtpu.ext_hdr_len =
	    gtpu_hdr_len0 - (sizeof (gtpu_header_t) - 4);
	  upf_buffer_opaque (b0)->gtpu.hdr_flags = gtpu0->ver_flags;
	  upf_buffer_opaque (b0)->gtpu.teid =
	    clib_net_to_host_u32 (gtpu0->teid);
	  upf_buffer_opaque (b0)->gtpu.pdr_idx =
	    !(pfcp_get_rules (t0, PFCP_ACTIVE)->flags & PFCP_CLASSIFY) ?
	    rule_index0 : ~0;
	  upf_buffer_opaque (b0)->gtpu.flow_id = ~0;

	  if (PREDICT_FALSE ((hdr_len0 + sizeof (*ip4_0)) >=
			     vlib_buffer_length_in_chain (vm, b0)))
	    {
	      error0 = UPF_GTPU_ERROR_LENGTH_ERROR;
	      next0 = UPF_GTPU_INPUT_NEXT_DROP;
	      goto trace00;
	    }

	  /* inner IP header */
	  ip4_0 = vlib_buffer_get_current (b0) + hdr_len0;
	  if ((ip4_0->ip_version_and_header_length & 0xF0) == 0x40)
	    next0 = (~0 == upf_buffer_opaque (b0)->gtpu.pdr_idx) ?
	      UPF_GTPU_INPUT_NEXT_IP4_FLOW_PROCESS :
	      UPF_GTPU_INPUT_NEXT_IP4_PROCESS;
	  else
	    next0 = (~0 == upf_buffer_opaque (b0)->gtpu.pdr_idx) ?
	      UPF_GTPU_INPUT_NEXT_IP6_FLOW_PROCESS :
	      UPF_GTPU_INPUT_NEXT_IP6_PROCESS;

	  pkts_decapsulated++;

	trace00:
	  b0->error = error0 ? node->errors[error0] : 0;

	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
	    {
	      gtpu_rx_trace_t *tr
		= vlib_add_trace (vm, node, b0, sizeof (*tr));
	      tr->next_index = next0;
	      tr->error = error0;
	      tr->session_index = session_index0;
	      tr->teid = clib_net_to_host_u32 (gtpu0->teid);
	    }

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }
  /* Do we still need this now that tunnel tx stats is kept? */
  vlib_node_increment_counter (vm, is_ip4 ?
			       upf_gtpu4_input_node.index :
			       upf_gtpu6_input_node.index,
			       UPF_GTPU_ERROR_DECAPSULATED,
			       pkts_decapsulated);

  return from_frame->n_vectors;
}


VLIB_NODE_FN (upf_gtpu4_input_node) (vlib_main_t * vm,
				     vlib_node_runtime_t * node,
				     vlib_frame_t * from_frame)
{
  return upf_gtpu_input (vm, node, from_frame, /* is_ip4 */ 1);
}

VLIB_NODE_FN (upf_gtpu6_input_node) (vlib_main_t * vm,
				     vlib_node_runtime_t * node,
				     vlib_frame_t * from_frame)
{
  return upf_gtpu_input (vm, node, from_frame, /* is_ip4 */ 0);
}

static char *upf_gtpu_error_strings[] = {
#define upf_gtpu_error(n,s) s,
#include <upf/upf_gtpu_error.def>
#undef upf_gtpu_error
#undef _
};

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (upf_gtpu4_input_node) = {
  .name = "upf-gtpu4-input",
  /* Takes a vector of packets. */
  .vector_size = sizeof (u32),

  .n_errors = UPF_GTPU_N_ERROR,
  .error_strings = upf_gtpu_error_strings,

  .n_next_nodes = UPF_GTPU_INPUT_N_NEXT,
  .next_nodes = {
    [UPF_GTPU_INPUT_NEXT_DROP]             = "error-drop",
    [UPF_GTPU_INPUT_NEXT_IP4_FLOW_PROCESS] = "upf-ip4-flow-process",
    [UPF_GTPU_INPUT_NEXT_IP6_FLOW_PROCESS] = "upf-ip6-flow-process",
    [UPF_GTPU_INPUT_NEXT_IP4_PROCESS]      = "upf-ip4-input",
    [UPF_GTPU_INPUT_NEXT_IP6_PROCESS]      = "upf-ip6-input",
    [UPF_GTPU_INPUT_NEXT_ERROR_INDICATION] = "upf-gtp-error-indication",
    [UPF_GTPU_INPUT_NEXT_ECHO_REQUEST]     = "upf-gtp-ip4-echo-request",
  },

  //temp  .format_buffer = format_gtpu_header,
  .format_trace = format_gtpu_rx_trace,
  // $$$$ .unformat_buffer = unformat_gtpu_header,
};
/* *INDENT-ON* */

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (upf_gtpu6_input_node) = {
  .name = "upf-gtpu6-input",
  /* Takes a vector of packets. */
  .vector_size = sizeof (u32),

  .n_errors = UPF_GTPU_N_ERROR,
  .error_strings = upf_gtpu_error_strings,

  .n_next_nodes = UPF_GTPU_INPUT_N_NEXT,
  .next_nodes = {
    [UPF_GTPU_INPUT_NEXT_DROP]             = "error-drop",
    [UPF_GTPU_INPUT_NEXT_IP4_FLOW_PROCESS] = "upf-ip4-flow-process",
    [UPF_GTPU_INPUT_NEXT_IP6_FLOW_PROCESS] = "upf-ip6-flow-process",
    [UPF_GTPU_INPUT_NEXT_IP4_PROCESS]      = "upf-ip4-input",
    [UPF_GTPU_INPUT_NEXT_IP6_PROCESS]      = "upf-ip6-input",
    [UPF_GTPU_INPUT_NEXT_ERROR_INDICATION] = "upf-gtp-error-indication",
    [UPF_GTPU_INPUT_NEXT_ECHO_REQUEST]     = "upf-gtp-ip6-echo-request",
  },

//temp  .format_buffer = format_gtpu_header,
  .format_trace = format_gtpu_rx_trace,
  // $$$$ .unformat_buffer = unformat_gtpu_header,
};
/* *INDENT-ON* */

typedef struct
{
  u32 session_index;
  u32 error;
  gtp_error_ind_t indication;
} gtpu_error_ind_trace_t;

static u8 *
format_gtpu_error_ind_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  gtpu_error_ind_trace_t *t = va_arg (*args, gtpu_error_ind_trace_t *);

  if (t->session_index != ~0)
    {
      s =
	format (s,
		"GTPU Error Indication from %U, for gtpu_session%d teid 0x%08x error %d",
		format_ip46_address, &t->indication.addr, IP46_TYPE_ANY,
		t->session_index, t->indication.teid, t->error);
    }
  else
    {
      s =
	format (s,
		"GTPU decap error - session for IP %U teid 0x%08x does not exist",
		format_ip46_address, &t->indication.addr, IP46_TYPE_ANY,
		t->indication.teid);
    }
  return s;
}

static void
decode_error_indication_ext_hdr (vlib_buffer_t * b, u8 next_ext_type,
				 gtp_error_ind_t * error)
{
  u8 *start, *end, *p;

  start = p = vlib_buffer_get_current (b);
  end = vlib_buffer_get_tail (b);

  while (next_ext_type != 0 && p < end)
    {
      u16 length = (*p++ * 4) - 2;

      if (end - p < length)
	break;

      switch (next_ext_type)
	{
	case 0x40:		/* UDP Port number */
	  if (length < 2)
	    break;

	  error->port = clib_net_to_host_unaligned_mem_u16 ((u16 *) p);
	  break;

	default:
	  break;
	}
      p += length;
      next_ext_type = *p++;
    }

  vlib_buffer_advance (b, p - start);
  return;
}

static int
decode_error_indication (vlib_buffer_t * b, gtp_error_ind_t * error)
{
  u8 *p = vlib_buffer_get_current (b);
  u8 *end = vlib_buffer_get_tail (b);
  u8 flag = 0;
  u16 length;
  while (p < end)
    {
      upf_debug ("IE: %d", *p);
      switch (*p++)
	{
	case 14:		/* Recovery */
	  upf_debug ("IE: Recovery");
	  p++;
	  break;

	case 16:		/* Tunnel Endpoint Identifier Data I */
	  upf_debug ("IE: TEID I, %d", end - p);
	  if ((flag & 1) | (end - p < 4))
	    return -1;
	  flag |= 1;
	  error->teid = clib_net_to_host_u32 (*(u32 *) p);
	  upf_debug ("IE: TEID I, 0x%08x", error->teid);
	  p += 4;
	  break;

	case 133:		/* GTP-U Peer Address */
	  upf_debug ("IE: Peer, %d", end - p);
	  if ((flag & 2) | (end - p < 2))
	    return -1;
	  flag |= 2;
	  length = clib_net_to_host_u16 (*(u16 *) p);
	  upf_debug ("IE: Peer Length, %d, %d", length, end - p);
	  p += 2;
	  if ((end - p) < length)
	    return -1;
	  if (length != 4 && length != 16)
	    return -1;
	  error->addr = to_ip46 (length == 16, p);
	  upf_debug ("IE: Peer %U", format_ip46_address, &error->addr,
		     IP46_TYPE_ANY);
	  p += length;
	  break;

	default:
	  return -1;
	}
    }

  if (flag != 3)
    return -1;

  return 0;
}

VLIB_NODE_FN (upf_gtp_error_ind_node) (vlib_main_t * vm,
				       vlib_node_runtime_t * node,
				       vlib_frame_t * frame)
{
  upf_main_t *gtm = &upf_main;
  u32 *buffers, *first_buffer;
  gtp_error_ind_t error;
  u32 n_errors_left;

  buffers = vlib_frame_vector_args (frame);
  first_buffer = buffers;

  n_errors_left = frame->n_vectors;

  while (n_errors_left >= 1)
    {
      gtpu_header_t *gtpu;
      upf_session_t *t;
      vlib_buffer_t *b;
      u32 session_index = ~0;
      u32 bi, err = 0;
      bi = buffers[0];

      buffers += 1;
      n_errors_left -= 1;

      b = vlib_get_buffer (vm, bi);
      UPF_CHECK_INNER_NODE (b);
      vlib_buffer_reset (b);
      vlib_buffer_advance (b, vnet_buffer (b)->l4_hdr_offset);
      gtpu = vlib_buffer_get_current (b);

      upf_debug ("P: %U", format_hex_bytes, gtpu, 16);
      upf_debug ("%p, TEID: %u, Flags: %02x, Ext: %u", gtpu,
		 gtpu->teid, gtpu->ver_flags & GTPU_E_S_PN_BIT,
		 gtpu->next_ext_type);

      memset (&error, 0, sizeof (error));

      if (PREDICT_FALSE ((gtpu->ver_flags & GTPU_E_S_PN_BIT) != 0))
	{
	  /* Pop gtpu header */
	  vlib_buffer_advance (b, sizeof (gtpu_header_t));

	  if ((gtpu->ver_flags & GTPU_E_BIT) != 0)
	    decode_error_indication_ext_hdr (b, gtpu->next_ext_type, &error);
	}
      else
	{
	  /* Pop gtpu header */
	  vlib_buffer_advance (b, sizeof (gtpu_header_t) - 4);
	}

      if (decode_error_indication (b, &error) != 0)
	{
	  err = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
	  goto trace;
	}

      if (ip46_address_is_ip4 (&error.addr))
	{
	  clib_bihash_kv_8_8_t kv, value;
	  gtpu4_tunnel_key_t key4;

	  key4.dst = error.addr.ip4.as_u32;
	  key4.teid = error.teid;

	  kv.key = key4.as_u64;

	  if (PREDICT_FALSE
	      (clib_bihash_search_8_8 (&gtm->v4_tunnel_by_key, &kv, &value)))
	    {
	      err = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
	      goto trace;
	    }
	  session_index = (value.value & 0xffffffff);
	}
      else
	{
	  clib_bihash_kv_24_8_t kv, value;

	  kv.key[0] = error.addr.ip6.as_u64[0];
	  kv.key[1] = error.addr.ip6.as_u64[1];
	  kv.key[2] = error.teid;

	  if (PREDICT_FALSE
	      (clib_bihash_search_24_8 (&gtm->v6_tunnel_by_key, &kv, &value)))
	    {
	      err = UPF_GTPU_ERROR_NO_SUCH_TUNNEL;
	      goto trace;
	    }
	  session_index = (value.value & 0xffffffff);
	}

      t = pool_elt_at_index (gtm->sessions, session_index);

      upf_pfcp_error_report (t, &error);

    trace:
      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
	{
	  gtpu_error_ind_trace_t *tr =
	    vlib_add_trace (vm, node, b, sizeof (*tr));
	  tr->session_index = session_index;
	  tr->error = err;
	  tr->indication = error;
	}
    }

  vlib_buffer_free (vm, first_buffer, frame->n_vectors);

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (upf_gtp_error_ind_node) = {
  .name = "upf-gtp-error-indication",
  .flags = VLIB_NODE_FLAG_IS_DROP,
  .vector_size = sizeof (u32),
  //  .format_buffer = format_ip4_header,
  .format_trace = format_gtpu_error_ind_trace,
};
/* *INDENT-ON* */

/****************************************************************************/

typedef enum
{
  UPF_GTPU_ECHO_REQ_NEXT_DROP,
  UPF_GTPU_ECHO_REQ_NEXT_REPLY,
  UPF_GTPU_ECHO_REQ_N_NEXT,
} gtpu_echo_req_next_t;

typedef struct
{
  u8 packet_data[64];
} gtpu_echo_req_trace_t;

static u8 *
format_gtpu_ip4_echo_req_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  gtpu_echo_req_trace_t *t = va_arg (*args, gtpu_echo_req_trace_t *);

  return format (s, "%U", format_ip4_header, t->packet_data,
		 sizeof (t->packet_data));
}

VLIB_NODE_FN (upf_gtp_ip4_echo_req_node) (vlib_main_t * vm,
					  vlib_node_runtime_t * node,
					  vlib_frame_t * frame)
{
  ip4_main_t *i4m = &ip4_main;
  uword n_packets = frame->n_vectors;
  u32 n_left_from, next_index, *from, *to_next;
  u16 *fragment_ids, *fid;
  u8 host_config_ttl = i4m->host_config.ttl;

  from = vlib_frame_vector_args (frame);
  n_left_from = n_packets;
  next_index = node->cached_next_index;

  if (node->flags & VLIB_NODE_FLAG_TRACE)
    vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
				   sizeof (from[0]),
				   sizeof (gtpu_echo_req_trace_t));

  /* Get random fragment IDs for replies. */
  fid = fragment_ids = clib_random_buffer_get_data (&vm->random_buffer,
						    n_packets *
						    sizeof (fragment_ids[0]));

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 next0 = UPF_GTPU_ECHO_REQ_NEXT_REPLY;
	  u32 error0 = UPF_GTPU_ERROR_ECHO_RESPONSES_SENT;
	  ip4_header_t *ip0;
	  udp_header_t *udp0;
	  gtpu_header_t *gtpu0;
	  vlib_buffer_t *p0;
	  u32 bi0;
	  ip4_address_t tmp0;
	  u16 port0;
	  ip_csum_t sum0;
	  gtpu_ie_recovery_t *gtpu_recovery0;
	  u16 new_len0, new_ip_len0;

	  bi0 = to_next[0] = from[0];

	  from += 1;
	  n_left_from -= 1;
	  to_next += 1;
	  n_left_to_next -= 1;

	  p0 = vlib_get_buffer (vm, bi0);
	  UPF_CHECK_INNER_NODE (p0);
	  ip0 = vlib_buffer_get_current (p0);
	  udp0 = ip4_next_header (ip0);

	  gtpu0 = (gtpu_header_t *) (udp0 + 1);
	  gtpu0->ver_flags &= ~(GTPU_E_BIT | GTPU_PN_BIT);
	  if (!(gtpu0->ver_flags & GTPU_S_BIT))
	    {
	      gtpu0->ver_flags |= GTPU_S_BIT;
	      gtpu0->sequence = 0;
	    }
	  gtpu0->type = GTPU_TYPE_ECHO_RESPONSE;
	  gtpu0->length =
	    clib_net_to_host_u16 (sizeof (gtpu_ie_recovery_t) + 4);
	  /*
	   * TS 29.281 5.1: for Echo Request/Response, 0 is always used
	   * for the response TEID
	   */
	  gtpu0->teid = 0;
	  gtpu0->pdu_number = 0;
	  gtpu0->next_ext_type = 0;
	  gtpu_recovery0 =
	    (gtpu_ie_recovery_t *) ((u8 *) (udp0 + 1) +
				    sizeof (gtpu_header_t));
	  gtpu_recovery0->ie_type = GTPU_IE_RECOVERY;
	  gtpu_recovery0->restart_counter = 0;

	  vnet_buffer (p0)->sw_if_index[VLIB_RX] =
	    vnet_main.local_interface_sw_if_index;

	  /* Swap source and destination address. */
	  tmp0 = ip0->src_address;
	  ip0->src_address = ip0->dst_address;
	  ip0->dst_address = tmp0;

	  /* Calculate new IP length. */
	  new_len0 = ip4_header_bytes (ip0) +
	    sizeof (udp_header_t) + sizeof (gtpu_header_t) +
	    sizeof (gtpu_ie_recovery_t);
	  p0->current_length = new_len0;

	  /* Update IP header fields and checksum. */
	  sum0 = ip0->checksum;

	  sum0 = ip_csum_update (sum0, ip0->ttl, host_config_ttl,
				 ip4_header_t, ttl);
	  ip0->ttl = host_config_ttl;

	  sum0 = ip_csum_update (sum0, ip0->fragment_id, fid[0],
				 ip4_header_t, fragment_id);
	  ip0->fragment_id = fid[0];
	  fid += 1;

	  new_ip_len0 = clib_host_to_net_u16 (new_len0);
	  sum0 = ip_csum_update (sum0, ip0->length, new_ip_len0,
				 ip4_header_t, length);
	  ip0->length = new_ip_len0;

	  ip0->checksum = ip_csum_fold (sum0);

	  ASSERT (ip0->checksum == ip4_header_checksum (ip0));

	  /* Swap source and destination port. */
	  port0 = udp0->src_port;
	  udp0->src_port = udp0->dst_port;
	  udp0->dst_port = port0;

	  /* UDP length. */
	  udp0->length = clib_host_to_net_u16 (sizeof (udp_header_t) +
					       sizeof (gtpu_header_t) +
					       sizeof (gtpu_ie_recovery_t));
	  /* UDP checksum. */
	  udp0->checksum = 0;
	  udp0->checksum = ip4_tcp_udp_compute_checksum (vm, p0, ip0);
	  if (udp0->checksum == 0)
	    udp0->checksum = 0xffff;

	  p0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;

	  vlib_error_count (vm, node->node_index, error0, 1);

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

static u8 *
format_gtpu_ip6_echo_req_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  gtpu_echo_req_trace_t *t = va_arg (*args, gtpu_echo_req_trace_t *);

  return format (s, "%U", format_ip6_header, t->packet_data,
		 sizeof (t->packet_data));
}

VLIB_NODE_FN (upf_gtp_ip6_echo_req_node) (vlib_main_t * vm,
					  vlib_node_runtime_t * node,
					  vlib_frame_t * frame)
{
  ip6_main_t *i6m = &ip6_main;
  uword n_packets = frame->n_vectors;
  u32 n_left_from, next_index, *from, *to_next;

  from = vlib_frame_vector_args (frame);
  n_left_from = n_packets;
  next_index = node->cached_next_index;

  if (node->flags & VLIB_NODE_FLAG_TRACE)
    vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
				   sizeof (from[0]),
				   sizeof (gtpu_echo_req_trace_t));

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 next0 = UPF_GTPU_ECHO_REQ_NEXT_REPLY;
	  u32 error0 = UPF_GTPU_ERROR_ECHO_RESPONSES_SENT;
	  ip6_header_t *ip0;
	  udp_header_t *udp0;
	  gtpu_header_t *gtpu0;
	  u32 fib_index0;
	  vlib_buffer_t *p0;
	  u32 bi0;
	  ip6_address_t tmp0;
	  u16 port0;
	  int bogus0;
	  gtpu_ie_recovery_t *gtpu_recovery0;
	  u16 new_len0;

	  bi0 = to_next[0] = from[0];

	  from += 1;
	  n_left_from -= 1;
	  to_next += 1;
	  n_left_to_next -= 1;

	  p0 = vlib_get_buffer (vm, bi0);
	  UPF_CHECK_INNER_NODE (p0);
	  ip0 = vlib_buffer_get_current (p0);
	  udp0 = ip6_next_header (ip0);

	  gtpu0 = (gtpu_header_t *) (udp0 + 1);
	  gtpu0->ver_flags &= ~(GTPU_E_BIT | GTPU_PN_BIT);
	  if (!(gtpu0->ver_flags & GTPU_S_BIT))
	    {
	      gtpu0->ver_flags |= GTPU_S_BIT;
	      gtpu0->sequence = 0;
	    }
	  gtpu0->type = GTPU_TYPE_ECHO_RESPONSE;
	  gtpu0->length =
	    clib_net_to_host_u16 (sizeof (gtpu_ie_recovery_t) + 4);
	  /*
	   * TS 29.281 5.1: for Echo Request/Response, 0 is always used
	   * for the response TEID
	   */
	  gtpu0->teid = 0;
	  gtpu0->pdu_number = 0;
	  gtpu0->next_ext_type = 0;
	  gtpu_recovery0 =
	    (gtpu_ie_recovery_t *) ((u8 *) (udp0 + 1) +
				    sizeof (gtpu_header_t));
	  gtpu_recovery0->ie_type = GTPU_IE_RECOVERY;
	  gtpu_recovery0->restart_counter = 0;

	  /* if the packet is link local, we'll bounce through the link-local
	   * table with the RX interface correctly set */
	  fib_index0 = vec_elt (i6m->fib_index_by_sw_if_index,
				vnet_buffer (p0)->sw_if_index[VLIB_RX]);
	  vnet_buffer (p0)->sw_if_index[VLIB_TX] = fib_index0;

	  /* Swap source and destination address. */
	  tmp0 = ip0->src_address;
	  ip0->src_address = ip0->dst_address;
	  ip0->dst_address = tmp0;

	  ip0->hop_limit = i6m->host_config.ttl;

	  /* Calculate new IP length. */
	  new_len0 =
	    sizeof (udp_header_t) + sizeof (gtpu_header_t) +
	    sizeof (gtpu_ie_recovery_t);
	  p0->current_length = sizeof (ip6_header_t) + new_len0;
	  ip0->payload_length = clib_host_to_net_u16 (new_len0);

	  /* Swap source and destination port. */
	  port0 = udp0->src_port;
	  udp0->src_port = udp0->dst_port;
	  udp0->dst_port = port0;

	  /* UDP length. */
	  udp0->length = ip0->payload_length;

	  /* UDP checksum. */
	  udp0->checksum = 0;
	  udp0->checksum =
	    ip6_tcp_udp_icmp_compute_checksum (vm, p0, ip0, &bogus0);
	  if (udp0->checksum == 0)
	    udp0->checksum = 0xffff;

	  p0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED;

	  vlib_error_count (vm, node->node_index, error0, 1);

	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (upf_gtp_ip4_echo_req_node) = {
  .name = "upf-gtp-ip4-echo-request",
  .vector_size = sizeof (u32),
  .format_trace = format_gtpu_ip4_echo_req_trace,

  .n_errors = UPF_GTPU_N_ERROR,
  .error_strings = upf_gtpu_error_strings,

  .n_next_nodes = UPF_GTPU_ECHO_REQ_N_NEXT,
  .next_nodes = {
    [UPF_GTPU_ECHO_REQ_NEXT_DROP] = "error-drop",
    [UPF_GTPU_ECHO_REQ_NEXT_REPLY] = "ip4-load-balance",
  },
};
/* *INDENT-ON* */

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (upf_gtp_ip6_echo_req_node) = {
  .name = "upf-gtp-ip6-echo-request",
  .vector_size = sizeof (u32),
  .format_trace = format_gtpu_ip6_echo_req_trace,

  .n_errors = UPF_GTPU_N_ERROR,
  .error_strings = upf_gtpu_error_strings,

  .n_next_nodes = UPF_GTPU_ECHO_REQ_N_NEXT,
  .next_nodes = {
    [UPF_GTPU_ECHO_REQ_NEXT_DROP] = "error-drop",
    [UPF_GTPU_ECHO_REQ_NEXT_REPLY] = "ip6-lookup",
  },
};
/* *INDENT-ON* */

/****************************************************************************/

typedef enum
{
  IP_GTPU_UPF_BYPASS_NEXT_DROP,
  IP_GTPU_UPF_BYPASS_NEXT_GTPU,
  IP_GTPU_UPF_BYPASS_N_NEXT,
} ip_vxan_bypass_next_t;

always_inline uword
ip_gtpu_upf_bypass_inline (vlib_main_t * vm,
			   vlib_node_runtime_t * node,
			   vlib_frame_t * frame, u32 is_ip4)
{
  //  upf_main_t * gtm = &upf_main;
  u32 *from, *to_next, n_left_from, n_left_to_next, next_index;
  vlib_node_runtime_t *error_node =
    vlib_node_get_runtime (vm, ip4_input_node.index);
#if VTEP_VALIDATION
  ip4_address_t addr4;		/* last IPv4 address matching a local VTEP address */
  ip6_address_t addr6;		/* last IPv6 address matching a local VTEP address */
#endif

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  if (node->flags & VLIB_NODE_FLAG_TRACE)
    ip4_forward_next_trace (vm, node, frame, VLIB_TX);

#if VTEP_VALIDATION
  if (is_ip4)
    addr4.data_u32 = ~0;
  else
    ip6_address_set_zero (&addr6);
#endif

  while (n_left_from > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from >= 4 && n_left_to_next >= 2)
	{
	  vlib_buffer_t *b0, *b1;
	  ip4_header_t *ip40, *ip41;
	  ip6_header_t *ip60, *ip61;
	  udp_header_t *udp0, *udp1;
	  u32 bi0, ip_len0, udp_len0, flags0, next0;
	  u32 bi1, ip_len1, udp_len1, flags1, next1;
	  i32 len_diff0, len_diff1;
	  u8 error0, good_udp0, proto0;
	  u8 error1, good_udp1, proto1;

	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t *p2, *p3;

	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);

	    vlib_prefetch_buffer_header (p2, LOAD);
	    vlib_prefetch_buffer_header (p3, LOAD);

	    CLIB_PREFETCH (p2->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
	    CLIB_PREFETCH (p3->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
	  }

	  bi0 = to_next[0] = from[0];
	  bi1 = to_next[1] = from[1];
	  from += 2;
	  n_left_from -= 2;
	  to_next += 2;
	  n_left_to_next -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);
	  if (is_ip4)
	    {
	      ip40 = vlib_buffer_get_current (b0);
	      ip41 = vlib_buffer_get_current (b1);
	    }
	  else
	    {
	      ip60 = vlib_buffer_get_current (b0);
	      ip61 = vlib_buffer_get_current (b1);
	    }

	  /* Setup packet for next IP feature */
	  vnet_feature_next (&next0, b0);
	  vnet_feature_next (&next1, b1);

	  if (is_ip4)
	    {
	      /* Treat IP frag packets as "experimental" protocol for now
	         until support of IP frag reassembly is implemented */
	      proto0 = ip4_is_fragment (ip40) ? 0xfe : ip40->protocol;
	      proto1 = ip4_is_fragment (ip41) ? 0xfe : ip41->protocol;
	    }
	  else
	    {
	      proto0 = ip60->protocol;
	      proto1 = ip61->protocol;
	    }

	  /* Process packet 0 */
	  if (proto0 != IP_PROTOCOL_UDP)
	    goto exit0;		/* not UDP packet */

	  if (is_ip4)
	    udp0 = ip4_next_header (ip40);
	  else
	    udp0 = ip6_next_header (ip60);

	  if (udp0->dst_port != clib_host_to_net_u16 (UDP_DST_PORT_GTPU))
	    goto exit0;		/* not GTPU packet */

#if VTEP_VALIDATION
	  /* TODO: list of VTEPs as reported by User Plane IP Resource Information
	   *
	   * a CLI cmd to configure a interfaces as GTP enabled and
	   * mark it ia Core, Access, SGi is needed....
	   */

	  /* Validate DIP against VTEPs */
	  if (is_ip4)
	    {
	      if (addr4.as_u32 != ip40->dst_address.as_u32)
		{
		  if (!hash_get (gtm->vtep4, ip40->dst_address.as_u32))
		    goto exit0;	/* no local VTEP for GTPU packet */
		  addr4 = ip40->dst_address;
		}
	    }
	  else
	    {
	      if (!ip6_address_is_equal (&addr6, &ip60->dst_address))
		{
		  if (!hash_get_mem (gtm->vtep6, &ip60->dst_address))
		    goto exit0;	/* no local VTEP for GTPU packet */
		  addr6 = ip60->dst_address;
		}
	    }
#endif

	  flags0 = b0->flags;
	  good_udp0 = (flags0 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;

	  /* Don't verify UDP checksum for packets with explicit zero checksum. */
	  good_udp0 |= udp0->checksum == 0;

	  /* Verify UDP length */
	  if (is_ip4)
	    ip_len0 = clib_net_to_host_u16 (ip40->length);
	  else
	    ip_len0 = clib_net_to_host_u16 (ip60->payload_length);
	  udp_len0 = clib_net_to_host_u16 (udp0->length);
	  len_diff0 = ip_len0 - udp_len0;

	  /* Verify UDP checksum */
	  if (PREDICT_FALSE (!good_udp0))
	    {
	      if ((flags0 & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED) == 0)
		{
		  if (is_ip4)
		    flags0 = ip4_tcp_udp_validate_checksum (vm, b0);
		  else
		    flags0 = ip6_tcp_udp_icmp_validate_checksum (vm, b0);
		  good_udp0 =
		    (flags0 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;
		}
	    }

	  if (is_ip4)
	    {
	      error0 = good_udp0 ? 0 : IP4_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP4_ERROR_UDP_LENGTH;
	    }
	  else
	    {
	      error0 = good_udp0 ? 0 : IP6_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP6_ERROR_UDP_LENGTH;
	    }

	  next0 = error0 ?
	    IP_GTPU_UPF_BYPASS_NEXT_DROP : IP_GTPU_UPF_BYPASS_NEXT_GTPU;
	  b0->error = error0 ? error_node->errors[error0] : 0;

	  /* gtpu-input node expect current at GTPU header */
	  if (is_ip4)
	    vlib_buffer_advance (b0,
				 sizeof (ip4_header_t) +
				 sizeof (udp_header_t));
	  else
	    vlib_buffer_advance (b0,
				 sizeof (ip6_header_t) +
				 sizeof (udp_header_t));

	exit0:
	  /* Process packet 1 */
	  if (proto1 != IP_PROTOCOL_UDP)
	    goto exit1;		/* not UDP packet */

	  if (is_ip4)
	    udp1 = ip4_next_header (ip41);
	  else
	    udp1 = ip6_next_header (ip61);

	  if (udp1->dst_port != clib_host_to_net_u16 (UDP_DST_PORT_GTPU))
	    goto exit1;		/* not GTPU packet */

#if VTEP_VALIDATION
	  /* TODO: list of VTEPs as reported by User Plane IP Resource Information
	   *
	   * a CLI cmd to configure a interfaces as GTP enabled and
	   * mark it ia Core, Access, SGi is needed....
	   */

	  /* Validate DIP against VTEPs */
	  if (is_ip4)
	    {
	      if (addr4.as_u32 != ip41->dst_address.as_u32)
		{
		  if (!hash_get (gtm->vtep4, ip41->dst_address.as_u32))
		    goto exit1;	/* no local VTEP for GTPU packet */
		  addr4 = ip41->dst_address;
		}
	    }
	  else
	    {
	      if (!ip6_address_is_equal (&addr6, &ip61->dst_address))
		{
		  if (!hash_get_mem (gtm->vtep6, &ip61->dst_address))
		    goto exit1;	/* no local VTEP for GTPU packet */
		  addr6 = ip61->dst_address;
		}
	    }
#endif

	  flags1 = b1->flags;
	  good_udp1 = (flags1 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;

	  /* Don't verify UDP checksum for packets with explicit zero checksum. */
	  good_udp1 |= udp1->checksum == 0;

	  /* Verify UDP length */
	  if (is_ip4)
	    ip_len1 = clib_net_to_host_u16 (ip41->length);
	  else
	    ip_len1 = clib_net_to_host_u16 (ip61->payload_length);
	  udp_len1 = clib_net_to_host_u16 (udp1->length);
	  len_diff1 = ip_len1 - udp_len1;

	  /* Verify UDP checksum */
	  if (PREDICT_FALSE (!good_udp1))
	    {
	      if ((flags1 & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED) == 0)
		{
		  if (is_ip4)
		    flags1 = ip4_tcp_udp_validate_checksum (vm, b1);
		  else
		    flags1 = ip6_tcp_udp_icmp_validate_checksum (vm, b1);
		  good_udp1 =
		    (flags1 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;
		}
	    }

	  if (is_ip4)
	    {
	      error1 = good_udp1 ? 0 : IP4_ERROR_UDP_CHECKSUM;
	      error1 = (len_diff1 >= 0) ? error1 : IP4_ERROR_UDP_LENGTH;
	    }
	  else
	    {
	      error1 = good_udp1 ? 0 : IP6_ERROR_UDP_CHECKSUM;
	      error1 = (len_diff1 >= 0) ? error1 : IP6_ERROR_UDP_LENGTH;
	    }

	  next1 = error1 ?
	    IP_GTPU_UPF_BYPASS_NEXT_DROP : IP_GTPU_UPF_BYPASS_NEXT_GTPU;
	  b1->error = error1 ? error_node->errors[error1] : 0;

	  /* gtpu-input node expect current at GTPU header */
	  if (is_ip4)
	    vlib_buffer_advance (b1,
				 sizeof (ip4_header_t) +
				 sizeof (udp_header_t));
	  else
	    vlib_buffer_advance (b1,
				 sizeof (ip6_header_t) +
				 sizeof (udp_header_t));

	exit1:
	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, bi1, next0, next1);
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  vlib_buffer_t *b0;
	  ip4_header_t *ip40;
	  ip6_header_t *ip60;
	  udp_header_t *udp0;
	  u32 bi0, ip_len0, udp_len0, flags0, next0;
	  i32 len_diff0;
	  u8 error0, good_udp0, proto0;

	  bi0 = to_next[0] = from[0];
	  from += 1;
	  n_left_from -= 1;
	  to_next += 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  if (is_ip4)
	    ip40 = vlib_buffer_get_current (b0);
	  else
	    ip60 = vlib_buffer_get_current (b0);

	  /* Setup packet for next IP feature */
	  vnet_feature_next (&next0, b0);

	  if (is_ip4)
	    /* Treat IP4 frag packets as "experimental" protocol for now
	       until support of IP frag reassembly is implemented */
	    proto0 = ip4_is_fragment (ip40) ? 0xfe : ip40->protocol;
	  else
	    proto0 = ip60->protocol;

	  if (proto0 != IP_PROTOCOL_UDP)
	    goto exit;		/* not UDP packet */

	  if (is_ip4)
	    udp0 = ip4_next_header (ip40);
	  else
	    udp0 = ip6_next_header (ip60);

	  if (udp0->dst_port != clib_host_to_net_u16 (UDP_DST_PORT_GTPU))
	    goto exit;		/* not GTPU packet */

#if VTEP_VALIDATION
	  /* TODO: list of VTEPs as reported by User Plane IP Resource Information
	   *
	   * a CLI cmd to configure a interfaces as GTP enabled and
	   * mark it ia Core, Access, SGi is needed....
	   */

	  /* Validate DIP against VTEPs */
	  if (is_ip4)
	    {
	      if (addr4.as_u32 != ip40->dst_address.as_u32)
		{
		  if (!hash_get (gtm->vtep4, ip40->dst_address.as_u32))
		    goto exit;	/* no local VTEP for GTPU packet */
		  addr4 = ip40->dst_address;
		}
	    }
	  else
	    {
	      if (!ip6_address_is_equal (&addr6, &ip60->dst_address))
		{
		  if (!hash_get_mem (gtm->vtep6, &ip60->dst_address))
		    goto exit;	/* no local VTEP for GTPU packet */
		  addr6 = ip60->dst_address;
		}
	    }
#endif

	  flags0 = b0->flags;
	  good_udp0 = (flags0 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;

	  /* Don't verify UDP checksum for packets with explicit zero checksum. */
	  good_udp0 |= udp0->checksum == 0;

	  /* Verify UDP length */
	  if (is_ip4)
	    ip_len0 = clib_net_to_host_u16 (ip40->length);
	  else
	    ip_len0 = clib_net_to_host_u16 (ip60->payload_length);
	  udp_len0 = clib_net_to_host_u16 (udp0->length);
	  len_diff0 = ip_len0 - udp_len0;

	  /* Verify UDP checksum */
	  if (PREDICT_FALSE (!good_udp0))
	    {
	      if ((flags0 & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED) == 0)
		{
		  if (is_ip4)
		    flags0 = ip4_tcp_udp_validate_checksum (vm, b0);
		  else
		    flags0 = ip6_tcp_udp_icmp_validate_checksum (vm, b0);
		  good_udp0 =
		    (flags0 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;
		}
	    }

	  if (is_ip4)
	    {
	      error0 = good_udp0 ? 0 : IP4_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP4_ERROR_UDP_LENGTH;
	    }
	  else
	    {
	      error0 = good_udp0 ? 0 : IP6_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP6_ERROR_UDP_LENGTH;
	    }

	  next0 = error0 ?
	    IP_GTPU_UPF_BYPASS_NEXT_DROP : IP_GTPU_UPF_BYPASS_NEXT_GTPU;
	  b0->error = error0 ? error_node->errors[error0] : 0;

	  /* gtpu-input node expect current at GTPU header */
	  if (is_ip4)
	    vlib_buffer_advance (b0,
				 sizeof (ip4_header_t) +
				 sizeof (udp_header_t));
	  else
	    vlib_buffer_advance (b0,
				 sizeof (ip6_header_t) +
				 sizeof (udp_header_t));

	exit:
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

VLIB_NODE_FN (ip4_gtpu_upf_bypass_node) (vlib_main_t * vm,
					 vlib_node_runtime_t * node,
					 vlib_frame_t * frame)
{
  return ip_gtpu_upf_bypass_inline (vm, node, frame, /* is_ip4 */ 1);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_gtpu_upf_bypass_node) = {
  .name = "ip4-gtpu-upf-bypass",
  .vector_size = sizeof (u32),

  .n_next_nodes = IP_GTPU_UPF_BYPASS_N_NEXT,
  .next_nodes = {
    [IP_GTPU_UPF_BYPASS_NEXT_DROP] = "error-drop",
    [IP_GTPU_UPF_BYPASS_NEXT_GTPU] = "upf-gtpu4-input",
  },

  .format_buffer = format_ip4_header,
  .format_trace = format_ip4_forward_next_trace,
};
/* *INDENT-ON* */

#ifndef CLIB_MARCH_VARIANT
/* Dummy init function to get us linked in. */
clib_error_t *
ip4_gtpu_upf_bypass_init (vlib_main_t * vm)
{
  return 0;
}

VLIB_INIT_FUNCTION (ip4_gtpu_upf_bypass_init);
#endif /* CLIB_MARCH_VARIANT */

VLIB_NODE_FN (ip6_gtpu_upf_bypass_node) (vlib_main_t * vm,
					 vlib_node_runtime_t * node,
					 vlib_frame_t * frame)
{
  return ip_gtpu_upf_bypass_inline (vm, node, frame, /* is_ip4 */ 0);
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip6_gtpu_upf_bypass_node) = {
  .name = "ip6-gtpu-upf_bypass",
  .vector_size = sizeof (u32),

  .n_next_nodes = IP_GTPU_UPF_BYPASS_N_NEXT,
  .next_nodes = {
    [IP_GTPU_UPF_BYPASS_NEXT_DROP] = "error-drop",
    [IP_GTPU_UPF_BYPASS_NEXT_GTPU] = "upf-gtpu6-input",
  },

  .format_buffer = format_ip6_header,
  .format_trace = format_ip6_forward_next_trace,
};
/* *INDENT-ON* */

#ifndef CLIB_MARCH_VARIANT
/* Dummy init function to get us linked in. */
clib_error_t *
ip6_gtpu_upf_bypass_init (vlib_main_t * vm)
{
  return 0;
}

VLIB_INIT_FUNCTION (ip6_gtpu_upf_bypass_init);
#endif /* CLIB_MARCH_VARIANT */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */
